<?php

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/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.1.6 or newer
 *
 * @package CodeIgniter
 * @author ExpressionEngine Dev Team
 * @copyright Copyright (c) 2008 - 2011, EllisLab, Inc.
 * @license http://codeigniter.com/user_guide/license.html
 * @link http://codeigniter.com
 * @since Version 1.0
 * @filesource
 *
 */
    
// ------------------------------------------------------------------------

/**
 * oci8 Database Adapter Class
 *
 * Note: _DB is an extender class that the app controller
 * creates dynamically based on whether the active record
 * class is being used or not.
 *
 * @package CodeIgniter
 * @subpackage Drivers
 * @category Database
 * @author ExpressionEngine Dev Team
 * @link http://codeigniter.com/user_guide/database/
 */

/**
 * oci8 Database Adapter Class
 *
 * This is a modification of the DB_driver class to
 * permit access to oracle databases
 *
 * @author Kelly McArdle
 *        
 */
class CI_DB_oci8_driver extends CI_DB
{

    var $dbdriver = 'oci8';
    
    // The character used for excaping
    var $_escape_char = '"';
    
    // clause and character used for LIKE escape sequences
    var $_like_escape_str = " escape '%s' ";

    var $_like_escape_chr = '!';

    /**
     * The syntax to count rows is slightly different across different
     * database engines, so this string appears in each driver and is
     * used for the count_all() and count_all_results() functions.
     */
    var $_count_string = "SELECT COUNT(1) AS ";

    var $_random_keyword = ' ASC';
 // not currently supported
                                   
    // Set "auto commit" by default
    var $_commit = OCI_COMMIT_ON_SUCCESS;
    
    // need to track statement id and cursor id
    var $stmt_id;

    var $curs_id;
    
    // if we use a limit, we will add a field that will
    // throw off num_fields later
    var $limit_used;

    /**
     * Non-persistent database connection
     *
     * @access private called by the base class
     * @return resource
     */
    public function db_connect ()
    {
        return @oci_connect($this->username, $this->password, $this->hostname, 
                $this->char_set);
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Persistent database connection
     *
     * @access private called by the base class
     * @return resource
     */
    public function db_pconnect ()
    {
        return @oci_pconnect($this->username, $this->password, $this->hostname, 
                $this->char_set);
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Reconnect
     *
     * Keep / reestablish the db connection if no queries have been
     * sent for a length of time exceeding the server's idle timeout
     *
     * @access public
     * @return void
     */
    public function reconnect ()
    {
        // not implemented in oracle
        return;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Select the database
     *
     * @access private called by the base class
     * @return resource
     */
    public function db_select ()
    {
        // Not in Oracle - schemas are actually usernames
        return TRUE;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Set client character set
     *
     * @access public
     * @param
     *            string
     * @param
     *            string
     * @return resource
     */
    public function db_set_charset ($charset, $collation)
    {
        // @todo - add support if needed
        return TRUE;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Version number query string
     *
     * @access protected
     * @return string
     */
    protected function _version ()
    {
        return oci_server_version($this->conn_id);
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Execute the query
     *
     * @access protected called by the base class
     * @param
     *            string an SQL query
     * @return resource
     */
    protected function _execute ($sql)
    {
        // oracle must parse the query before it is run. All of the actions with
        // the query are based on the statement id returned by ociparse
        $this->stmt_id = FALSE;
        $this->_set_stmt_id($sql);
        oci_set_prefetch($this->stmt_id, 1000);
        return @oci_execute($this->stmt_id, $this->_commit);
    }

    /**
     * Generate a statement ID
     *
     * @access private
     * @param
     *            string an SQL query
     * @return none
     */
    private function _set_stmt_id ($sql)
    {
        if (! is_resource($this->stmt_id)) {
            $this->stmt_id = oci_parse($this->conn_id, $this->_prep_query($sql));
        }
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Prep the query
     *
     * If needed, each database adapter can prep the query string
     *
     * @access private called by execute()
     * @param
     *            string an SQL query
     * @return string
     */
    private function _prep_query ($sql)
    {
        return $sql;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * getCursor.
     * Returns a cursor from the datbase
     *
     * @access public
     * @return cursor id
     */
    public function get_cursor ()
    {
        $this->curs_id = oci_new_cursor($this->conn_id);
        return $this->curs_id;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Stored Procedure.
     * Executes a stored procedure
     *
     * @access public
     * @param
     *            package package stored procedure is in
     * @param
     *            procedure stored procedure to execute
     * @param
     *            params array of parameters
     * @return array params array keys
     *        
     *         KEY OPTIONAL NOTES
     *         name no the name of the parameter should be in :<param_name>
     *         format
     *         value no the value of the parameter. If this is an OUT or IN OUT
     *         parameter,
     *         this should be a reference to a variable
     *         type yes the type of the parameter
     *         length yes the max size of the parameter
     */
    public function stored_procedure ($package, $procedure, $params)
    {
        if ($package == '' or $procedure == '' or ! is_array($params)) {
            if ($this->db_debug) {
                log_message('error', 'Invalid query: ' . $package . '.' .
                         $procedure);
                return $this->display_error('db_invalid_query');
            }
            return FALSE;
        }
        
        // build the query string
        $sql = "begin $package.$procedure(";
        
        $have_cursor = FALSE;
        foreach ($params as $param) {
            $sql .= $param['name'] . ",";
            
            if (array_key_exists('type', $param) &&
                     ($param['type'] === OCI_B_CURSOR)) {
                $have_cursor = TRUE;
            }
        }
        $sql = trim($sql, ",") . "); end;";
        
        $this->stmt_id = FALSE;
        $this->_set_stmt_id($sql);
        $this->_bind_params($params);
        $this->query($sql, FALSE, $have_cursor);
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Bind parameters
     *
     * @access private
     * @return none
     */
    private function _bind_params ($params)
    {
        if (! is_array($params) or ! is_resource($this->stmt_id)) {
            return;
        }
        
        foreach ($params as $param) {
            foreach (array(
                    'name',
                    'value',
                    'type',
                    'length'
            ) as $val) {
                if (! isset($param[$val])) {
                    $param[$val] = '';
                }
            }
            
            oci_bind_by_name($this->stmt_id, $param['name'], $param['value'], 
                    $param['length'], $param['type']);
        }
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Begin Transaction
     *
     * @access public
     * @return bool
     */
    public function trans_begin ($test_mode = FALSE)
    {
        if (! $this->trans_enabled) {
            return TRUE;
        }
        
        // When transactions are nested we only begin/commit/rollback the
        // outermost ones
        if ($this->_trans_depth > 0) {
            return TRUE;
        }
        
        // Reset the transaction failure flag.
        // If the $test_mode flag is set to TRUE transactions will be rolled
        // back
        // even if the queries produce a successful result.
        $this->_trans_failure = ($test_mode === TRUE) ? TRUE : FALSE;
        
        $this->_commit = OCI_DEFAULT;
        return TRUE;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Commit Transaction
     *
     * @access public
     * @return bool
     */
    public function trans_commit ()
    {
        if (! $this->trans_enabled) {
            return TRUE;
        }
        
        // When transactions are nested we only begin/commit/rollback the
        // outermost ones
        if ($this->_trans_depth > 0) {
            return TRUE;
        }
        
        $ret = oci_commit($this->conn_id);
        $this->_commit = OCI_COMMIT_ON_SUCCESS;
        return $ret;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Rollback Transaction
     *
     * @access public
     * @return bool
     */
    public function trans_rollback ()
    {
        if (! $this->trans_enabled) {
            return TRUE;
        }
        
        // When transactions are nested we only begin/commit/rollback the
        // outermost ones
        if ($this->_trans_depth > 0) {
            return TRUE;
        }
        
        $ret = oci_rollback($this->conn_id);
        $this->_commit = OCI_COMMIT_ON_SUCCESS;
        return $ret;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Escape String
     *
     * @access public
     * @param
     *            string
     * @param
     *            bool whether or not the string will be used in a LIKE
     *            condition
     * @return string
     */
    public function escape_str ($str, $like = FALSE)
    {
        if (is_array($str)) {
            foreach ($str as $key => $val) {
                $str[$key] = $this->escape_str($val, $like);
            }
            
            return $str;
        }
        
        $str = remove_invisible_characters($str);
        
        // escape LIKE condition wildcards
        if ($like === TRUE) {
            $str = str_replace(array(
                    '%',
                    '_',
                    $this->_like_escape_chr
            ), 
                    array(
                            $this->_like_escape_chr . '%',
                            $this->_like_escape_chr . '_',
                            $this->_like_escape_chr . $this->_like_escape_chr
                    ), $str);
        }
        
        return $str;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Affected Rows
     *
     * @access public
     * @return integer
     */
    public function affected_rows ()
    {
        return @oci_num_rows($this->stmt_id);
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Insert ID
     *
     * @access public
     * @return integer
     */
    public function insert_id ()
    {
        // not supported in oracle
        return $this->display_error('db_unsupported_function');
    }
    
    // --------------------------------------------------------------------
    
    /**
     * "Count All" query
     *
     * Generates a platform-specific query string that counts all records in
     * the specified database
     *
     * @access public
     * @param
     *            string
     * @return string
     */
    public function count_all ($table = '')
    {
        if ($table == '') {
            return 0;
        }
        
        $query = $this->query(
                $this->_count_string . $this->_protect_identifiers('numrows') .
                         " FROM " .
                         $this->_protect_identifiers($table, TRUE, NULL, FALSE));
        
        if ($query == FALSE) {
            return 0;
        }
        
        $row = $query->row();
        $this->_reset_select();
        return (int) $row->numrows;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Show table query
     *
     * Generates a platform-specific query string so that the table names can be
     * fetched
     *
     * @access protected
     * @param
     *            boolean
     * @return string
     */
    protected function _list_tables ($prefix_limit = FALSE)
    {
        $sql = "SELECT TABLE_NAME FROM ALL_TABLES";
        
        if ($prefix_limit !== FALSE and $this->dbprefix != '') {
            $sql .= " WHERE TABLE_NAME LIKE '" .
                     $this->escape_like_str($this->dbprefix) . "%' " .
                     sprintf($this->_like_escape_str, $this->_like_escape_chr);
        }
        
        return $sql;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Show column query
     *
     * Generates a platform-specific query string so that the column names can
     * be fetched
     *
     * @access protected
     * @param
     *            string the table name
     * @return string
     */
    protected function _list_columns ($table = '')
    {
        return "SELECT COLUMN_NAME FROM all_tab_columns WHERE table_name = '$table'";
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Field data query
     *
     * Generates a platform-specific query so that the column data can be
     * retrieved
     *
     * @access public
     * @param
     *            string the table name
     * @return object
     */
    protected function _field_data ($table)
    {
        return "SELECT * FROM " . $table . " where rownum = 1";
    }
    
    // --------------------------------------------------------------------
    
    /**
     * The error message string
     *
     * @access protected
     * @return string
     */
    protected function _error_message ()
    {
        // If the error was during connection, no conn_id should be passed
        $error = is_resource($this->conn_id) ? oci_error($this->conn_id) : oci_error();
        return $error['message'];
    }
    
    // --------------------------------------------------------------------
    
    /**
     * The error message number
     *
     * @access protected
     * @return integer
     */
    protected function _error_number ()
    {
        // Same as _error_message()
        $error = is_resource($this->conn_id) ? oci_error($this->conn_id) : oci_error();
        return $error['code'];
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Escape the SQL Identifiers
     *
     * This function escapes column and table names
     *
     * @access protected
     * @param
     *            string
     * @return string
     */
    protected function _escape_identifiers ($item)
    {
        if ($this->_escape_char == '') {
            return $item;
        }
        
        foreach ($this->_reserved_identifiers as $id) {
            if (strpos($item, '.' . $id) !== FALSE) {
                $str = $this->_escape_char .
                         str_replace('.', $this->_escape_char . '.', $item);
                
                // remove duplicates if the user already included the escape
                return preg_replace('/[' . $this->_escape_char . ']+/', 
                        $this->_escape_char, $str);
            }
        }
        
        if (strpos($item, '.') !== FALSE) {
            $str = $this->_escape_char .
                     str_replace('.', 
                            $this->_escape_char . '.' . $this->_escape_char, 
                            $item) . $this->_escape_char;
        } else {
            $str = $this->_escape_char . $item . $this->_escape_char;
        }
        
        // remove duplicates if the user already included the escape
        return preg_replace('/[' . $this->_escape_char . ']+/', 
                $this->_escape_char, $str);
    }
    
    // --------------------------------------------------------------------
    
    /**
     * From Tables
     *
     * This function implicitly groups FROM tables so there is no confusion
     * about operator precedence in harmony with SQL standards
     *
     * @access protected
     * @param
     *            type
     * @return type
     */
    protected function _from_tables ($tables)
    {
        if (! is_array($tables)) {
            $tables = array(
                    $tables
            );
        }
        
        return implode(', ', $tables);
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Insert statement
     *
     * Generates a platform-specific insert string from the supplied data
     *
     * @access public
     * @param
     *            string the table name
     * @param
     *            array the insert keys
     * @param
     *            array the insert values
     * @return string
     */
    protected function _insert ($table, $keys, $values)
    {
        return "INSERT INTO " . $table . " (" . implode(', ', $keys) .
                 ") VALUES (" . implode(', ', $values) . ")";
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Insert_batch statement
     *
     * Generates a platform-specific insert string from the supplied data
     *
     * @access protected
     * @param
     *            string the table name
     * @param
     *            array the insert keys
     * @param
     *            array the insert values
     * @return string
     */
    protected function _insert_batch ($table, $keys, $values)
    {
        $keys = implode(', ', $keys);
        $sql = "INSERT ALL\n";
        
        for ($i = 0, $c = count($values); $i < $c; $i ++) {
            $sql .= '	INTO ' . $table . ' (' . $keys . ') VALUES ' . $values[$i] .
                     "\n";
        }
        
        $sql .= 'SELECT * FROM dual';
        
        return $sql;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Update statement
     *
     * Generates a platform-specific update string from the supplied data
     *
     * @access protected
     * @param
     *            string the table name
     * @param
     *            array the update data
     * @param
     *            array the where clause
     * @param
     *            array the orderby clause
     * @param
     *            array the limit clause
     * @return string
     */
    protected function _update ($table, $values, $where, $orderby = array(), 
            $limit = FALSE)
    {
        foreach ($values as $key => $val) {
            $valstr[] = $key . " = " . $val;
        }
        
        $limit = (! $limit) ? '' : ' LIMIT ' . $limit;
        
        $orderby = (count($orderby) >= 1) ? ' ORDER BY ' .
                 implode(", ", $orderby) : '';
        
        $sql = "UPDATE " . $table . " SET " . implode(', ', $valstr);
        
        $sql .= ($where != '' and count($where) >= 1) ? " WHERE " .
                 implode(" ", $where) : '';
        
        $sql .= $orderby . $limit;
        
        return $sql;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Truncate statement
     *
     * Generates a platform-specific truncate string from the supplied data
     * If the database does not support the truncate() command
     * This function maps to "DELETE FROM table"
     *
     * @access protected
     * @param
     *            string the table name
     * @return string
     */
    protected function _truncate ($table)
    {
        return "TRUNCATE TABLE " . $table;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Delete statement
     *
     * Generates a platform-specific delete string from the supplied data
     *
     * @access protected
     * @param
     *            string the table name
     * @param
     *            array the where clause
     * @param
     *            string the limit clause
     * @return string
     */
    protected function _delete ($table, $where = array(), $like = array(), $limit = FALSE)
    {
        $conditions = '';
        
        if (count($where) > 0 or count($like) > 0) {
            $conditions = "\nWHERE ";
            $conditions .= implode("\n", $this->ar_where);
            
            if (count($where) > 0 && count($like) > 0) {
                $conditions .= " AND ";
            }
            $conditions .= implode("\n", $like);
        }
        
        $limit = (! $limit) ? '' : ' LIMIT ' . $limit;
        
        return "DELETE FROM " . $table . $conditions . $limit;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Limit string
     *
     * Generates a platform-specific LIMIT clause
     *
     * @access protected
     * @param
     *            string the sql query string
     * @param
     *            integer the number of rows to limit the query to
     * @param
     *            integer the offset value
     * @return string
     */
    protected function _limit ($sql, $limit, $offset)
    {
        $limit = $offset + $limit;
        $newsql = "SELECT * FROM (select inner_query.*, rownum rnum FROM ($sql) inner_query WHERE rownum < $limit)";
        
        if ($offset != 0) {
            $newsql .= " WHERE rnum >= $offset";
        }
        
        // remember that we used limits
        $this->limit_used = TRUE;
        
        return $newsql;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Close DB Connection
     *
     * @access protected
     * @param
     *            resource
     * @return void
     */
    protected function _close ($conn_id)
    {
        @oci_close($conn_id);
    }
}



/* End of file oci8_driver.php */
/* Location: ./system/database/drivers/oci8/oci8_driver.php */
